(someone) is caught in (their) sandbag

Translations
(кого-то) поймали в (его) ловушку
She was caught in her sandbag when the backup plan failed.
Её поймали в её ловушку, когда запасной план провалился.
Definitions
This phrase means that someone is trapped or hindered by their own actions, plans, or defenses—often something they set up to protect themselves or gain an advantage, but which ends up restricting or backfiring on them.